Look, I don't know you. I don't know your fantasy team. I don't know which clever team name you went with (I hope it was "Ethier Said Than Dunn") and I don't know what Nomar Garciaparra is talking about most of the times he commentates games.
But I do know this: I know why fantasy baseball teams lose. (Most of the time.) It's actually not all that hard. All it takes is access to stats and the ability to empathize.
It's possible your team lost last week because you forgot to change your lineup twice, and you still haven't dropped Mariano Rivera. But just in case you're oblivious as to any tangible reason why you just got tagged with that "L" in your head-to-head league, here are 10 possible factors (some within and some out of your control) that could've played a part in leading to your loss.